Field of the Invention
The present invention relates to a coating film-removing method for a cylindrical substrate and a manufacturing method for an electrophotographic photosensitive member.
Description of the Related Art
In an electrophotographic photosensitive member to be used in a copying machine, a laser beam printer, or the like, for example, an electro-conductive layer, an undercoat layer, a charge generating layer, a charge transporting layer, and the like are arranged on a cylindrical substrate. As a manufacturing method for such electrophotographic photosensitive member, there is known a method involving forming, on the substrate, a coating film of a coating liquid for each of the above-mentioned layers constituting the electrophotographic photosensitive member (electrophotographic photosensitive member coating liquid), and heating and curing the coating film. In particular, a dip coating method, which involves dipping the cylindrical substrate in the electrophotographic photosensitive member coating liquid while, for example, an axis of the substrate is in a vertical direction, and then pulling up the substrate to form the coating film, has been widely adopted because of its high productivity. However, in the dip coating method, the coating film is inevitably formed on an outer peripheral surface of a lower side of the substrate as well.
In this connection, the copying machine or the laser beam printer adopts the following construction in some cases: a member (roller) for keeping a constant distance between the electrophotographic photosensitive member and a developing member (such as a developing sleeve) is caused to abut against the electrophotographic photosensitive member. In those cases, a portion against which the roller abuts is subjected to rubbing, and hence the presence of a coating film at such portion involves a problem in that the coating film is nonuniformly peeled or abraded. Therefore, it is necessary that the coating film be not formed at such portion.
Under the above-mentioned circumstances, when the coating film is formed on the cylindrical substrate by the dip coating method, there is required a step of removing an unnecessary coating film on the outer peripheral surface of the lower side of the substrate after coating film formation.
Accordingly, there is a proposal of an apparatus configured to remove a coating film at a lower end portion of a photosensitive member. For example, in Japanese Patent Application Laid-Open No. H11-212278, there is known an apparatus configured to dip a lower end portion of a photosensitive member in a solvent capable of dissolving a coating film and rotate a wiping plate, to thereby remove an unnecessary coating film. In addition, in Japanese Patent Application Laid-Open No. 2001-205178, there is proposed an apparatus configured to discharge a solvent from an apparatus inserted at a lower end on the inside of a cylindrical substrate and rub a coating film with a brush, to thereby remove the coating film.